Pahrump you have already overshot DVNP.
I am in OC and I take 395 to Trona road to Searles Valley and up over the hill on CA190.
I always see people with motorcycles etc boondocked along Trona Road. You could find something there. Not sure about permits as I go in one swoop.
CA190 has a long 7% to 9% grade both up and down. Downshift and go slow and you will be fine. I make it. All roads in require a steep grade.
You could stop in Yermo KOA and visit the touristy Calico Ghost town if you want to get about half way. I think you can camp at Calico too.
https://parks.sbcounty.gov/park/calico-ghost-town-regional-park/From Yermo you can continue on 15 and turn left at Baker to enter from the SE. Or cut back onto 395 and enter from the West. Or go in one, out the other for a big loop.
No need to try and see it all. Too big. Give yourself extra time with that little one.